Question on molarity

[spoog74]

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question is;

What is the molarity of a solution of H2SO4 if 100mL of this solution requires 25mL of 2.0 M of NaOH

Now, my answer was 1, because i mutiplied the final molarity (.5) by 2 because H2SO4 has 2 moles of H+ ions...

But the final answer was .25 , insead of MULTIPLING they DIVIDED by 2.

Can someone tell me why? Every problem ive done like this has always been with multiplying the amount of H+ or OH by the final molarity...

Thanks all

 

[casper22]

question is;

What is the molarity of a solution of H2SO4 if 100mL of this solution requires 25mL of 2.0 M of NaOH

Now, my answer was 1, because i mutiplied the final molarity (.5) by 2 because H2SO4 has 2 moles of H+ ions...

But the final answer was .25 , insead of MULTIPLING they DIVIDED by 2.

Can someone tell me why? Every problem ive done like this has always been with multiplying the amount of H+ or OH by the final molarity...

Thanks all

You are doing this correctly but as a safe practice multiply the 2 initially, so basically the equation is:

N1V1 = N2V2
2N1 x 100 = 25 x 2

solving this will give you N1 = 1/4 = 0.25

 

[spoog74]

You are doing this correctly but as a safe practice multiply the 2 initially, so basically the equation is:

N1V1 = N2V2
2N1 x 100 = 25 x 2

solving this will give you N1 = 1/4 = 0.25

Great, thank you